There are on the market radio receivers having a data memory in which the transmitters being received are stored, with their PI codes and their alternative frequencies, in the sequence of their reception.
Also known, from German Pat. No. DE 39 17 263 A1, are data memories in which there is associated with each memory cell for an alternative frequency an evaluation memory which registers how often it is received.
In the known radio receivers, when a change occurs in the program being received, a check is first made as to whether the PI code associated with the program just selected, and the carrier frequency being received, are already stored. When, for example, the result is only that the number in the evaluation memory is incremented because the carrier frequency is already stored.